10. ringing, measuring, tracking

[marika.solo]

2018

Age estimation of black stork (Ciconia nigra) nestlings from wing, bill, head, and tarsus lengths at the time of ringing

Abstract
Black stork nestlings were measured (wing, bill, head, and tarsus lengths) at weekly intervals in central Poland in 2012, 2014, and 2015. The aim of the study was to provide growth equations based on nestling measurements to allow age estimation of black stork nestlings. The hatching hour and date of nestlings in five nests were determined using trail cameras. The age of the measured nestlings ranged from 18 to 53 days. Wing, bill, and head lengths showed linear growth, while tarsus growth was only linear for nestlings not exceeding 35 days old. Within the age range studied, wing length grew 9.6 mm per day, head length grew 2.3 mm per day, and bill length grew 1.8 mm per day. The study provides the first growth parameters for the black stork.

- According to our experience, the safest time window to ring nestlings is between 30 and 40 days after hatching.
- ... the ringing of nestlings older than 40 days might cause some nestlings to fall from the nest, because they at first try to frighten an intruder with aggressive behaviour and later move to the nest rim. This is particularly dangerous in large broods when four or five large nestlings wave wings at the nest edge, potentially knocking each other from the nest.
- ... to diminish the stress suffered by nestlings during ringing and to increase nestling safety, it is highly recommended to use a small blanket to cover all the nestlings immediately after the ringer arrives at the nest.

KAMINSKI, MACIEJ; JANIC, BARTOSZ; MARSZAL, LIDIA; BANBURA, JERZY; and ZIELINSKI, PIOTR (2018) "Age estimation of black stork (Ciconia nigra) nestlings from wing, bill, head, and tarsus lengths at the time of ringing," Turkish Journal of Zoology: Vol. 42: No. 1, Article 17. https://doi.org/10.3906/zoo-1702-42
Available at: https://journals.tubitak.gov.tr/zoology/vol42/iss1/17